Issue #67

Sep/Oct 2008

The emulation of analog gear in the digital realm is nothing new, but the emulation of analog gear in the analog realm is a new concept-analog modeling. AnaMod was founded in 2006 by two long-time industry innovators, Dave Amels (Bomb Factory, Voce, Tape Op #31) and Greg Gualtieri (Pendulum Audio, Tape Op #38). AnaMod products are entirely analog and do not process audio in the digital domain, yet the same patented mathematical modeling found in digital plug-ins for Bomb Factory has been applied to the creation of AnaMod's all-analog products. The company's trademarked (and also patented) AnaMod Process takes a mathematical model and implements it using analog building blocks. At first glance, it may seem like the company is building recreations of vintage gear, but when you realize that they've fit their version of a Fairchild tube compressor into a single 500-series solid-state module (the recently released AM660), the AnaMod concept begins to stand out. Additionally, there's no D-A or A-D conversion, no latency, no hidden fees for software upgrades, and no system incompatibility limitations. Hardware emulating hardware-an interesting concept, indeed.
Now imagine that you're mixing a record, and there is a machine room with four tape decks, say a 3M M79, a Studer A800, an Ampex 351 and an ATR-102, all running like tops. Also in the room is the industry's best tape-op waiting to throw on fresh reels of GP9, 456 or new-old-stock Scotch 111, transfer your tracks to the fresh reel, and calibrate the tape decks instantly to taste. Let's also include instant re-biasing, the ability to completely remove or add as much hiss as you want, and miraculously, the ability to hear your mix without the coloration of the tape or the deck (hard bypass). Welcome to AnaMod's ATS-1 Analog Tape Simulator.
The ATS-1 is a 2RU-height stereo unit with the look and feel of an old Ampex 350, sporting a silver front, black vintage-style knobs, two well-lit VU output meters, and two illuminated, square record and stop buttons that engage and bypass the unit, respectively. Large input and output knobs for each channel are the only individual L/R controls, leaving the rest to affect both channels simultaneously. Some of the controls correspond directly to the settings and alignment pots you find on a real tape deck: Bias level; HF Repro level (a treble boost/cut on the playback circuit); LF Record level (a bass boost/cut on the record circuit); Tape Speed (7.5, 15, and 30 IPS); and a meter calibration switch, allowing the user to go from 0 dB (185 nWb/m), up to +12 dB in 3 dB steps, effectively simulating the standard "overs" at which we often calibrate for different tape formulas and/or desired coloration and compression. There's also a knob to add Hiss (from none to way too much). Two rotary switches select from up to four tape machine and four tape formula models. Each model is a user-installable "personality card" that fits into a slot inside the unit. Doing the math, there are 48 different selectable combinations (4 decks x 4 tapes x 3 speeds), and those can all be infinitely tweaked with the other controls. The ATS-1 is certainly the most complex and thorough tape-emulation system out there to date, offering an enormous range of subtle shades of harmonic complexity.
Given the vastness of possibilities, it would be nearly impossible to test the accuracy of each model combination. Besides, simulations always sound a bit different than the real thing, and when you're dealing with vintage gear, especially old tape-decks that have been repeatedly serviced, running relatively inconsistent tape formulas (some of which have not been manufactured in decades), you're never going to have consistency from one machine to another, or even on the same machine from one day to the next. So why worry too much about consistency from real to simulated? However, let me quickly say that the ATS-1 really sounds and behaves like a tape deck. When you push the inputs, the low-end builds up and the dynamic range begins to shrink, eventually giving way to a dark, crunchy distortion. When you slow down the deck, the characteristic bump in the low end and a slight loss of air ensue. When you under-bias the tape, you hear sibilance in the highs and fuzzy harmonic distortion in the lows. Because you're controlling parameters that are named after-and behave like-those you'd find on a tape deck, you end up thinking within the analog tape paradigm, something I don't seem to get to do enough these days. (If only the ATS-1 could also recreate the more humane pacing of a session with wait-times for the transport to rewind and the tapes to be changed.)
You certainly don't need knowledge of analog tape technology to get usable sounds out of the ATS-1, but such knowledge gives one insight into what these controls are doing within the modeled circuit and helped me feel confident operating it right away. Reversing that logic, the ATS-1 could be an excellent place to begin to learn analog tape technology. What does going +6 on an A800 running GP9 sound like at 15 IPS? Turn a few knobs and-more or less-find out!
While mixing in the box (Pro Tools HD is my box), one of the most important things I do is to run my entire mix through an analog 2-bus chain in order to add harmonic complexity, girth, depth, width, mojo and vibe. It's not a revolutionary technique at this point, but one that begs for constant refinement and expansion. Depending on the material, I use many combinations of analog gear, but my typical chain is a Cranesong HEDD 192 D-A converter to 1073s (either Vintech or real Neve, depending on where I am) to an API 2500 stereo bus compressor and back into the HEDD for tape and tube simulation and A-D conversion back into Pro Tools. I think of it this way: Pro Tools is my multitrack, often accentuated as such with Cranesong Phoenix, Massey Tape-Head, and other "color" plug-ins; the 1073s and the API (or whichever line-driver and compressor) give me my console coloration; and the HEDD's tube and tape emulation is my 2-track deck. Replacing the HEDD's processing with the ATS-1 as my simulated 2-track machine was a great way to get to know the unit, and I imagine, one of the more common ways people will use it.
On a mix I recently did for NYC-based musician and singer Jonah Smith, I was working on a slower, soulful tune featuring bass, drums, Wurlitzer piano, electric guitars, effected guitar loops, horns, strings, lead vocals, and a full back-up vocal section (all beautifully produced by the venerable Malcolm Burn). I was very happy with my mix using the HEDD processing to emulate my 2-track deck, yet was curious to hear the ATS-1 at work on this lovely, complex mix. As a general rundown, here's what I heard at 30 IPS with the bias and EQs set neutrally: the M79 deck made the low-mids punch and softened the top end; the A800 deck gave me a slightly more open top-end and focused the low-end; the 351 was lush, deep, and even fuzzy (probably a result of emulating tubes) and sounded most like the HEDD's pentode and tape emulators combined; the ATR-102 produced a narrower image overall and gave the mids a nice smoothness. I can't get into all of the combinations with the three tape formulas. However, the general vibe is that the GP9 simulation is the most hi-fi with a tighter bottom; 456 sounded fatter on the bottom, smooth in the highs, and a bit compressed; and 111 was more closed on top and the most compressed overall. On this mix, my favorite was the 351 running GP9, which gave the horns and strings an added sense of depth, while adding a glowing aura to the whole soundfield.
Now, imagine trying all this again at 15 IPS, now 7.5 IPS, now while driving the inputs a bit for more compression and coloration, now while varying the bias, and now while adding and subtracting treble and bass from the repro and record circuits respectively. It's an immensely vast palette of tape-style subtleties.
Next I strapped the ATS-1 to a soloed drum submix and found myself leaning toward 15 IPS, Studer A800, and 111 tape for a really punchy kick drum, a softening of the cymbals, and a nice forwardness in the snare. It was nice to know that, should this be too dark in the overall mix, I could change the setting quickly to make things sparkle, perhaps moving to GP9 at 30 IPS.
Want to get bass to growl a bit? Try running Scotch 111 on the Ampex 351 at 7.5 IPS. Nice. In fact, there's a whole world of tonal shaping to be done on the 7.5 IPS setting, which, to my ears, brought the most color out of all the different deck and tape models.
After about a week of mixing with the ATS-1, I noticed my thinking and vocabulary shifting to the paradigm of analog tape. This was the first time in my Pro Tools mix room that I'd begun to think in terms of IPS, biasing, or "running at +6", and it was certainly the first time I'd thought things like, "let's switch it over to GP9 and see how it sounds", or "throw it on the 351 and give it a whirl". I always welcome a paradigm shift and found this aspect of using the ATS-1 in a digital studio really refreshing.
In the days when all stages of recording were, by necessity, done on tape, it was standard practice to hit tape during tracking, hit it again during a bounce or two, and then hit the 2-track tape during mixing. That layering of harmonic complexity helped form the sound of what are generally
regarded as the hi-fidelity masterpieces of modern recording (fill in your favorite example here). Using the ATS-1 to build harmonic complexity throughout the various stages of recording, starting with tracking, can help one create more distinctively colored recordings in the digital realm. I found that an electric bass recorded through the ATS-1 sat way better with a drum submix that was run though the same settings and that hitting both of those again with the ATS-1 during mixdown really glued the rhythm section together. Gradually building up harmonic saturation always seems to work better for me than hitting any track just once. As my mother would say, "It's cold out there, so layer up!"
Similarly, when working in many different studios, tracking with the ATS-1 might help the project gain a sonic consistency it might not otherwise have. Think of it as tracking to the same reel of tape for each session. No matter where you are, the sound of that reel will help define the sound of the record. And toting a 2RU unit is far easier than lugging multiple reels of tape.
Unexpectedly, perhaps the most interesting features on the ATS-1 are the bias and hiss knobs. Bias (more specifically AC bias) is basically a high-frequency signal (generally around 100 kHz but as high as 423 kHz for the ATR-100 series) added to the signal going to tape that activates the magnetic particles to improve the linearity of the medium, and subsequently, the fidelity. If you don't understand bias, don't worry; there are many-including me-who consider the physics behind it a mystery. But the audible effect of bias on the recording is not a mystery, and those who work with analog tape know that the proper amount of bias can dramatically improve frequency response, reduce distortion, and increase signal-to-noise ratio.
Whatever the AnaMod team did in the creation of the bias control, they created something truly unique in today's market and could easily package the bias and hiss controls as a separate stereo unit (if that's even possible without the deck and tape models running). Why should they do this? Because these two knobs can change the nature of the program material in ways I just don't think you can get from any other piece of gear, aside from an actual tape machine (where hiss is not optional!). Let's put it this way: "biasing" a digital mix is a trip.
On a mix of thirteen horn players (bones, saxes, tuba, bass clarinet, trumpets) improvising a somber, tumbling dirge of "Amazing Grace", hiss was absolutely useful and lovely. Pushed too far, it was just hiss, but bled in carefully, it added a lovely layer of sonic gauze that gently filled the dark spaces between the widely panned sections. Perhaps this is nothing more than associative conditioning on my part-just me hearing hiss as a part of the world I expect free jazz and "Amazing Grace" to occupy. However, by over-biasing a bit, I was able to cramp the frequency response just enough to reign the hiss back in. The result is hard to describe, but I'd say I was able to unite the different voices without losing any of their individual clarity. In my book, that's an accomplishment, and something mastering engineers in particular might want to check out as an alternative noise-shaping (dithering) method. Bias and hiss are certainly part of that "analog magic" we are prone to love.
Along similar lines, the bias and hiss controls can be used together as an untraditional but oddly effective noise-reduction scheme. On a mix for a solo electric guitar performance (think Eno and Glass playing for a Transcendental Guru), the guitar was DI'ed from a Line 6 Echo Pro into a 1073 and then a Requisite L2M tube limiter. Nice chain-except that the echo unit introduced some noise with which I wasn't happy once I was bringing things up to broadcast (post-mastered) level. Again, by adding a subtle amount of hiss and really over-biasing the Studer A80 running GP9 at 30 IPS, I had one of the most effective noise-reduction units I've ever used.
How does the ATS-1 stack up against my Cranesong HEDD, the Cranesong Phoenix plug-in, and the Massey Tape-Head plug-in? In overall character, it's closest to Phoenix, creating a smooth, subtle coloration of the signal, and with increasing compression and coloration artifacts appearing as you drive the unit harder. With Phoenix's five different flavors and three different colors, these two are the closest. Compared to the HEDD, the ATS-1 is far more versatile, but generates a very different kind of color. The HEDD's tube emulations generate depth in the soundfield that only the 351 model came close to, and I think this points to the accuracy of the modeling of the ATS-1 (and the HEDD). The ATS-1 is furthest in sound from Massey Tape-Head, a plug-in I love to death for its ability to wake up a dead guitar or snare, for example. All told, it's a real treat to have all these different processors on hand to add different types of harmonic complexity to whatever I'm working on, but only the ATS-1 had me thinking and feeling like I was actually working with real tape.
In comparisons with recordings actually made to tape, I was limited to work I've done on an Otari MTR-90 2" with 16-track heads calibrated at +4 running GP9 at 15 IPS, and mixes run to a Studer A80 1/4" 2-track running GP9 at 30 IPS, so there are obvious obstacles in the way of an apples-to-apples comparison here. But listening to the tape recordings against the ATS-1 only furthered my belief that AnaMod is onto something with their simulation methods, as the general vibe is very similar. On a Billy Nayer Show tune I recorded and mixed to the Studer 2-track and to Pro Tools, I got very close to emulating the analog sound using the ATS-1's Studer A800 model, but actually appreciated what some of the other combinations were doing better. Again, for me, this box is about having that magic machine room with all those decks and reels. (Also, don't underestimate the importance of adding hiss when trying to match a digital recording to a tape!)
I want to stress that the sonic impact of the ATS-1 (and of tape in general) is subtle, even hard for the inexperienced ear to hear. Hearing the difference between the tape formulas, and how they react to being driven differently, is something akin to tasting wine and being able to identify the wood of the aging barrels. At $2995 list, the ATS-1 might be a hard sell for those who can't taste the wood, so to speak.
However, for those who grasp and desire the power to impact the subconscious of the listener with subtle colorations of sound, I'll say that the ATS-1 is currently the most versatile and powerful piece of kit on the market in this category, with just about no competition. And I can't stress enough how important a box like this can be to the professional mixer working in the box, especially if you're missing the vibe of tape. I would also expect that mastering engineers are going to love the ATS-1, especially when there's that album tracked to tape except for the one Mbox home-job, or when working a re-mastering job where the sound of a particular deck would show respect for the original, or when challenged with sonic inconsistencies across a diversely produced record. I can think of more than one mastering session where the ATS-1 would have been really helpful in pulling things together. Moreover, for mastering, we're dealing with hardware, which is easily integrated into the facility and eliminates the need for cross-platform compatibility. Mastering engineers should really check out the ATS-1.
My hat is off to the AnaMod team for taking a truly novel approach to gear design and opening up a whole new field of development in recording gear. I look forward to new personality cards for the ATS-1 and to more analog models in the future. Bring it on! ($2995 MSRP; www.anamodaudio.com)

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